Material: Silicone Feature: 1) Can be called reflective slap wrap, reflective bracelet, magic ruler,using as ruler 2) Hold the reflective surface upward and hold tightly one end of the reflective band 3) Tap the wrist / ankle gently to let it wind around 4) To straighten unwind the strap and stretch it until it makes a sound like a "crack" Size: 23x2.5cm